Streamline tutorial docs

Fixes #634 
Replaces repetitive tutorials with an "Examples" section in "Getting Started", with much simplified structure and tutorials replaced with more minimal example Flocker config files and instructions.
As it is only a few documents, I'd just diff the documents as they are in master, and as they were in this branch (the deleted column in this diff). Or maybe look at the git log for each of those documents and see what has happened in the last couple of days.